# Copyright (c) Alibaba, Inc. and its affiliates.
import inspect
import os
import shutil
import tempfile
from types import MethodType
from typing import Any, Dict, List, Mapping, Optional, Tuple, Union

import torch
import torch.nn as nn
from modelscope.hub.utils.utils import get_cache_dir
from peft import PeftModel
from transformers import FeatureExtractionMixin, GenerationConfig, PreTrainedModel, PreTrainedTokenizerBase
from transformers import ProcessorMixin as HfProcessorMixin

from swift.utils import deep_getattr, get_logger

try:
    from transformers import BaseImageProcessor
    Processor = Union[PreTrainedTokenizerBase, BaseImageProcessor, FeatureExtractionMixin, HfProcessorMixin]
except ImportError:
    Processor = Union[PreTrainedTokenizerBase, FeatureExtractionMixin, HfProcessorMixin]

if 'TOKENIZERS_PARALLELISM' not in os.environ:
    os.environ['TOKENIZERS_PARALLELISM'] = 'false'

logger = get_logger()

Tool = Dict[str, Union[str, Dict]]
History = List[Union[Tuple[str, str], List[str]]]
Message = Dict[str, Union[str, List[Dict[str, Any]], List[int], None]]
Messages = List[Message]


class ProcessorMixin:

    @property
    def tokenizer(self):
        tokenizer = self.processor
        if not isinstance(tokenizer, PreTrainedTokenizerBase) and hasattr(tokenizer, 'tokenizer'):
            tokenizer = tokenizer.tokenizer
        return tokenizer

    @tokenizer.setter
    def tokenizer(self, value):
        if self.processor is self.tokenizer:
            self.processor = value
        elif self.tokenizer is not value:
            raise AttributeError('Please use `self.processor` for assignment.')


def to_float_dtype(data: Any, dtype: torch.dtype) -> Any:
    """Change the float inputs to a dtype"""
    if isinstance(data, Mapping):
        return type(data)({k: to_float_dtype(v, dtype) for k, v in data.items()})
    elif isinstance(data, (tuple, list)):
        return type(data)(to_float_dtype(v, dtype) for v in data)
    elif isinstance(data, torch.Tensor) and torch.is_floating_point(data):
        return data.to(dtype=dtype)
    else:
        return data


def to_device(data: Any, device: Union[str, torch.device, int], non_blocking: bool = False) -> Any:
    """Move inputs to a device"""
    if isinstance(data, Mapping):
        return type(data)({k: to_device(v, device, non_blocking) for k, v in data.items()})
    elif isinstance(data, (tuple, list)):
        return type(data)(to_device(v, device, non_blocking) for v in data)
    elif isinstance(data, torch.Tensor):
        return data.to(device=device, non_blocking=non_blocking)
    else:
        return data


def set_generation_config(model: nn.Module, generation_config: GenerationConfig) -> None:
    old_generation_config = getattr(model, 'generation_config', None)
    old_generation_priority_config = ['no_repeat_ngram_size', 'num_beams']
    if old_generation_config is not None:
        for k, old_v in dir(old_generation_config).items():
            if k.startswith('_'):
                continue
            v = getattr(generation_config, k, None)
            if k in old_generation_priority_config or old_v is not None and v is None:
                setattr(generation_config, k, old_v)
    model.generation_config = generation_config


def find_module_list(model) -> Optional[nn.ModuleList]:
    module_lists = []
    for m in model.modules():
        if hasattr(m, 'gradient_checkpointing') or m.__class__.__name__ == 'CheckpointWrapper':
            return
        if (isinstance(m, (nn.ModuleList, nn.Sequential)) and len(m) >= 10
                and 'mlp' not in m[0].__class__.__name__.lower()):  # fix moe
            module_lists.append(m)
    if module_lists:
        return max(module_lists, key=lambda x: len(x))


def _kwargs_to_args(func, args, kwargs) -> Optional[List[Any]]:
    parameters = inspect.signature(func).parameters
    args = list(args)
    parameters = list(parameters.items())[len(args):]
    for key, param in parameters:
        if key in kwargs:
            args.append(kwargs[key])
        elif param.default != param.empty:
            args.append(param.default)
        else:
            return
    return args


def _add_gradient_checkpointing(module_list):

    requires_grad = None

    def _new_forward(self, *args, **kwargs):
        nonlocal requires_grad
        if requires_grad is None:
            requires_grad = any(p.requires_grad for p in self.parameters())

        new_args = _kwargs_to_args(self.__old_forward, args, kwargs)
        if new_args is not None and self.gradient_checkpointing and self.training:
            if new_args and isinstance(new_args[0], torch.Tensor) and requires_grad and not new_args[0].requires_grad:
                new_args[0].requires_grad_(True)
            layer_ret = self._gradient_checkpointing_func(self.__old_forward, *new_args)
            logger.info_once('Successfully using dynamic gradient checkpointing.')
        else:
            layer_ret = self.__old_forward(*args, **kwargs)
        return layer_ret

    for module in module_list:
        module.gradient_checkpointing = False
        if hasattr(module, '_old_forward'):  # device_map
            __old_forward = module._old_forward
            module._old_forward = MethodType(_new_forward, module)
        else:
            __old_forward = module.forward
            module.forward = MethodType(_new_forward, module)
        module.__old_forward = __old_forward


def dynamic_gradient_checkpointing(model, including_vit: bool = False) -> None:
    from .model import ModelMeta
    if isinstance(model, PeftModel):
        model = model.model
    model_meta: ModelMeta = getattr(model, 'model_meta', None)
    if model_meta is not None and model_meta.is_multimodal and model_meta.model_arch:
        tower_names = model_meta.model_arch.language_model.copy()
        if including_vit:
            tower_names += model_meta.model_arch.vision_tower
    else:
        tower_names = [None]

    model.supports_gradient_checkpointing = True
    for tower_name in tower_names:
        if tower_name is None:
            model_tower = model
        else:
            model_tower = deep_getattr(model, tower_name)
        model_tower.supports_gradient_checkpointing = True
        module_list = find_module_list(model_tower)
        if module_list is None:
            continue
        _add_gradient_checkpointing(module_list)
        logger.info(f'Automatically add gradient_checkpointing to {model_tower.__class__}.')


def history_to_messages(history: History,
                        system: Optional[str] = None,
                        roles: Optional[List[List[str]]] = None) -> 'Messages':
    """
    history: [['query1', 'response1'], ['query2', 'response2']]
        or [['query1', 'response1'], ['query2', None]]
    """
    messages = []
    if not roles:
        roles = [['user', 'assistant']] * len(history)
    else:
        assert len(roles) == len(history), f'len(roles): {len(roles)}, len(history): {len(history)}'
    if system is not None:
        messages.append({'role': 'system', 'content': system})

    for role, h in zip(roles, history):
        assert isinstance(h, (list, tuple))
        if h[0] is not None:
            messages.append({'role': role[0], 'content': h[0]})
        if h[1] is not None:
            messages.append({'role': role[1], 'content': h[1]})
    return messages


def messages_to_history(messages: 'Messages') -> Dict[str, Any]:
    system = None
    messages = messages.copy()
    if messages[0]['role'] == 'system':
        system = messages[0]['content']
        messages = messages[1::]
    if len(messages) % 2 == 1:
        messages.append({'role': 'assistant', 'content': None})
    history = []
    history_roles = []
    for user_message, assistant_message in zip(messages[::2], messages[1::2]):
        assert user_message['role'] in {'tool', 'user'}, f'user_message {user_message}'
        assert assistant_message['role'] == 'assistant', f'assistant_message: {assistant_message}'
        history.append([user_message['content'], assistant_message['content']])
        history_roles.append([user_message['role'], assistant_message['role']])
    query, response = history.pop() if history else (None, None)
    query_role = history_roles.pop()[0] if history_roles else None
    return {
        'history': history,
        'history_roles': history_roles,
        'query': query,
        'query_role': query_role,
        'response': response,
        'system': system,
    }


def save_checkpoint(model: Optional[PreTrainedModel],
                    processor: 'Processor',
                    output_dir: str,
                    *,
                    safe_serialization: bool = True,
                    max_shard_size: Union[int, str] = '5GB',
                    model_dirs: List[str] = None,
                    additional_saved_files: Optional[List[str]] = None) -> None:
    if model is not None:
        if model.__class__.__name__ != 'SentenceTransformer':
            model.save_pretrained(output_dir, safe_serialization=safe_serialization, max_shard_size=max_shard_size)
        else:
            model.save_pretrained(output_dir, safe_serialization=safe_serialization)
            # copy sentencetransformers files
            from swift.utils import copy_files_by_pattern
            copy_files_by_pattern(model.model_dir, output_dir, '*.py')
            copy_files_by_pattern(model.model_dir, output_dir, '*.json')
    processor.save_pretrained(output_dir)

    if model_dirs is None:
        model_dirs = []
    else:
        model_dirs = model_dirs.copy()
    if model and model.model_dir and model.model_dir not in model_dirs:
        model_dirs.append(model.model_dir)
    for src_file in (additional_saved_files or []) + ['preprocessor_config.json', 'args.json']:
        tgt_path = os.path.join(output_dir, src_file)
        if os.path.exists(tgt_path) and src_file == 'args.json':
            continue
        for model_dir in model_dirs:
            src_path: str = os.path.join(model_dir, src_file)
            if os.path.isfile(src_path):
                shutil.copy(src_path, tgt_path)
                break
            elif os.path.isdir(src_path):
                shutil.copytree(src_path, tgt_path)
                break


TEMP_DIR_POOL = {}


def get_temporary_cache_files_directory(prefix=None):
    if prefix is None:
        import datasets.config
        prefix = datasets.config.TEMP_CACHE_DIR_PREFIX
    global TEMP_DIR_POOL
    if prefix in TEMP_DIR_POOL:
        TEMP_DIR = TEMP_DIR_POOL[prefix]
    else:
        tmp_dir = os.path.join(get_cache_dir(), 'tmp')
        os.makedirs(tmp_dir, exist_ok=True)
        kwargs = {}
        parameters = inspect.signature(tempfile.TemporaryDirectory.__init__).parameters
        if 'ignore_cleanup_errors' in parameters:
            kwargs['ignore_cleanup_errors'] = True
        TEMP_DIR = tempfile.TemporaryDirectory(prefix=prefix, dir=tmp_dir, **kwargs)
        logger.info(f'create tmp_dir: {TEMP_DIR.name}')
        TEMP_DIR_POOL[prefix] = TEMP_DIR

    return TEMP_DIR.name


def get_ckpt_dir(model_dir: str, adapters_dir: Optional[List[str]]) -> str:
    model_dirs = (adapters_dir or []).copy()
    if model_dir:
        model_dirs.append(model_dir)
    # The adapter takes higher priority.
    ckpt_dir = None
    for model_dir in model_dirs:
        if os.path.exists(os.path.join(model_dir, 'args.json')):
            ckpt_dir = model_dir
            break
    return ckpt_dir


def update_generation_config_eos_token(generation_config, template):
    if generation_config is None:
        return
    stop_words = template.template_meta.stop_words
    eos_token_id = generation_config.eos_token_id
    if eos_token_id is None:
        eos_token_id = []
    elif isinstance(eos_token_id, int):
        eos_token_id = [eos_token_id]
    modified = False
    for stop_word in stop_words:
        if stop_word is None:
            continue
        if isinstance(stop_word, str):
            stop_word = template._tokenize(stop_word)
        if isinstance(stop_word, (list, tuple)) and len(stop_word) == 1 and stop_word[0] not in eos_token_id:
            eos_token_id.append(stop_word[0])
            modified = True
    if modified:
        generation_config.eos_token_id = eos_token_id


def get_packed_seq_params(position_ids: torch.Tensor):
    assert position_ids.shape[0] == 1, f'position_ids.shape: {position_ids.shape}'
    position_ids_f = position_ids.flatten()
    indices_q = torch.arange(position_ids_f.shape[0], device=position_ids_f.device, dtype=torch.int32)

    cu_seqlens = torch.cat([
        indices_q[position_ids_f == 0],
        torch.tensor(position_ids_f.shape, device=position_ids_f.device, dtype=torch.int32),
    ])

    max_length = cu_seqlens.diff().max()  # position_ids_f.max() + 1
    return {
        'cu_seq_lens_q': cu_seqlens,
        'cu_seq_lens_k': cu_seqlens,
        'max_length_q': max_length,
        'max_length_k': max_length,
    }
